Dead, discarded fish, highly contaminated with industrial pollutants, is the main item being used in the manufacturing of fishmeal (fed to poultry), the toxicity of which does not wear off even when the fish is boiled at high temperatures, said environmentalists. If anything, these compounds change form from one compound to the other during this process.

Mohammed Azhar, a lecturer at the Institute of Environmental Studies, University of Karachi, said the level of toxicity depends on the nature of the pollutant. He said that keeping seafood at high temperatures means that its protein content is lost. Hence, the drying and processing of discarded fish through boilers will decrease its nutrition value.

If it has 90 per cent protein content, it will go down to 10 per cent while it is being dried in the boiler. Sometimes the fish loses its entire protein content in this process, he added. Some organic arsenic compounds are also extensively added to poultry feed to improve growth rates by controlling parasitic diseases. Three-nitro-4-hydroxyphenylarsonic acid is currently the most commonly used arsenic compound in poultry feed with a usage of 23 to 45 grams of chemical per ton of feed for broiler chickens to increase the weight, feed efficiency, improve pigmentation and to prevent the spread of parasites.

Chander Perkash, Head of the Occupational Health Safety Environment (KESC) said that in some of the areas, poultry feed is being produced by using tannery wastes without necessary treatment and sterilisation. He pointed out that the poultry feed produced from tannery wastes without sterilisation is harmful to both the birds and consumers of eggs and chicken.

The problem stems from the fact that poultry feed producers don’t always use scientific methods and don’t go by health and hygiene standards. Tannery waste along with dried fish and bone is being used to feed young broiler and layer chickens. About 250 different toxic chemicals and heavy metals like cadmium, chromium, arsenic, zinc, etc, are being used by the leather industry. Their effluents have been high in the biological oxygen demand (BOD), which is particularly dangerous to consumers of poultry and related products.

When contacted, a fish grinding unit owner, Mengharam Mangwani, said that they have a lengthy process to make seafood usable (edible for chickens) after drying it in an open grounds in scorching heat for a few days and boiling it properly.

“We send samples of ground fish for laboratory tests and get certificates that are produced before supplying the product to fishmeal manufacturers. Hence it is not harmful for poultry,” he claimed.

Earlier, fishmeal manufacturers tried to import soybean as an alternate because it was hard to obtain fish from the local market. But now soybean is more expensive than the discarded fish. According to Mangwani, each grinder unit needs at least six million kilograms of fish annually to sustain the business but it hardly receives less than four million kilograms, which is insufficient to meet the demands of the buyers.

He said that earlier, there were hardly any fish grinding units in Ibrahim Hyderi and Bin Qasim Town, but now the number of factories has gone up to 50. Now, fishmeal manufacturers use less fish to make the feed. For instance, earlier they mixed 11kgs of fish into a 50kg fishmeal bag but now they are compelled to use hardly two per cent of the total fish to prepare the feed, because, Mangwani claimed, there is no more discarded fish in the local market. This will affect the protein content which is important for chicken growth.

Poultry feed roughly constitutes 70 per cent grain, 10 per cent protein, 10 per cent fibre and 10 per cent various other vitamins and minerals. Protein is an important component and apart from blood, meat and bone meal, it is extracted from the discarded fish meal that caters solely to the need for a protein source in poultry feed.